Gun-cartridge.



PATENTBD NOV.l 3, 1903.

,Wi C. BUSH.

GUN CARTRIDGE.

APPLICATION FILED APB. 29. 1903.

No MODEL.

creasing development UNITED STATES Patented November 3, 1903.

' ArnNr rrrcn.

GUN-CARTINE)(E.

SPECIFICATION forming part of Letters Patent No. 743,242, dated November 3, 1903.

Application llled April 29, 1903. Serial No. 154,865.

(No model.)

To @ZZ whom t may oon/eerie:

Beit known that I, WILLIAM C. BUSH, a citizen ofthe United States,residing in Wilmington, Delaware, have invented certain Improvements in Gun-Cartridges, of which the following is a specification.

The object of my invention is to so construct the base-block of a cartridge-shell as to provide in a more effective manner than before for the gradual increase in the rate 0f combustion of the explosive charge at the beginning of said period of combustion. This object I attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in whicl1.

Figure l isa sectional View, on an enltrged scale, of a cartridge-shell constrncteC- in aocordance withmy invention; and Fig. 2 is a similar view illustrating another form of my improved cartridge-shell.

l represents the casing of the shell, and 2 the base-block at the breech of the same, this base-block having the usual recess 3 for the reception of the primer. The inner face of the breech-block presents a succession of steps 4, leading from the dame-opening to the shell 1, so as to provide at the base of the charged shell a mass of powder which gradually increases in bulk'from the flame-opening onward, thereby causing a gradually-inof power when the combustion of the charge begins; In the cartridge shown'in Fig. 2 substantially the same eect is obtained by coiling a tapered strip of the material constituting the baseblock so as to provide a spiral seat instead of the succession of parallel steps.

I am aware that it has been proposed to provide acartridge with a base-block having aconical opening therein; but in such case the packing of the explosive into the shell causes a lateral forcing togetherof the particles contained in said conical opening, and this compacting of the explosive causes a more rapid combustion of the same and substantially neutralizes the effect of the cone in 'producing a gradually-increasing rate of combustion due to the gradually-increasing bulk of the explosive. My improved baseblock, however, while providingl a substantially conical powder-chamber, presents a succession of shelves which are substantially at right angles to the axial line of the cartridge. Hence there is no wedge-like action, such as that of a straight-sided cone, and the compacting' of the particlesof explosive at the base of the shell is prevented.

Having thus described my invention, I claim as new and desire to secure by Letters Patent- 1. A cartridge-shell having a base consist.- ing,r of a series of steps'forming a substantially conical powder-chamber, substantially as specified.

2.' A cartridge-shell having a base presentinga continuous spiral ledge which surrounds asubstantially conical powder-chamber, substantiallyas specified.

In testimony whereof I have signed my name to this specification in thc presence of two subscribing witnesses.

WILLIAM C. BUSH. 

